<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>04_作用域_面试题</title>
</head>
<body>
<script type="text/javascript">
    var x = 10;
    function fn() {
        console.log(x);
    }
    function show(f) {
        x = 20;
        fn()
    }
    show(fn);
</script>
</body>
</html>
